/**
 * Copyright 2009 The Apache Software Foundation
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.hadoop.hbase.io;

import java.util.*;

/**
 * A Static Interface.
 * Instead of having this code in the the HbaseMapWritable code, where it
 * blocks the possibility of altering the variables and changing their types,
 * it is put here in this static interface where the static final Maps are
 * loaded one time. Only byte[] and Cell are supported at this time.
 */
public interface CodeToClassAndBack {
	/**
	 * Static map that contains mapping from code to class
	 */
	public static final Map<Byte, Class<?>> CODE_TO_CLASS = new HashMap<Byte, Class<?>>();

	/**
	 * Static map that contains mapping from class to code
	 */
	public static final Map<Class<?>, Byte> CLASS_TO_CODE = new HashMap<Class<?>, Byte>();

	/**
	 * Class list for supported classes
	 */
	public Class<?>[] classList = { byte[].class };

	/**
	 * The static loader that is used instead of the static constructor in
	 * HbaseMapWritable.
	 */
	public InternalStaticLoader sl = new InternalStaticLoader(classList, CODE_TO_CLASS, CLASS_TO_CODE);

	/**
	 * Class that loads the static maps with their values.
	 */
	public class InternalStaticLoader {
		InternalStaticLoader(Class<?>[] classList, Map<Byte, Class<?>> CODE_TO_CLASS, Map<Class<?>, Byte> CLASS_TO_CODE) {
			byte code = 1;
			for (int i = 0; i < classList.length; i++) {
				CLASS_TO_CODE.put(classList[i], code);
				CODE_TO_CLASS.put(code, classList[i]);
				code++;
			}
		}
	}
}
